Of actions, etc.: Done or proceeding in secret or in the dark; kept concealed; hence, dark, of evil or deceitful nature. Obsolete.

Secret, obscure.

Hidden, concealed, secret.

Secret. Obsolete.

Secret. (Frequent in Layamon.) Obsolete.

figurative. Concealed, hidden, secret; disguised.

Characterized by reserve or secrecy. Phrase, in secre wyse.

Kept from knowledge or observation; hidden, concealed. Predicatively (esp. in to keep secret): Kept from public knowledge, or from the knowledge of…

= secret, adj. Obsolete. rare. (Used for rhyme.)

Concealed, hidden; secret; of concealed or ambiguous meaning. Obsolete.

Hidden from view or knowledge; concealed; kept secret. Frequently in to keep (something) dark: to keep (something) concealed; to keep secret.

(under-, prefix1 affix 2a(a).)

Concealed, secret, occult, etc.: see hide, v.1

Hidden, disguised; kept secret.

Concealed, hidden; secret. Obsolete.

†Secret.

Secret, concealed; unconfessed. Obsolete.

in secret: in private, not openly or in public; secretly. †at one's secret: to oneself, privately. †of secret: of a secret character.

Secret, concealed; = mystical, adj. 5. Obsolete. rare.

Secret, clandestine; = subterranean, adj. 3.

Recondite, abstruse. Cf. recherché, adj. Obsolete. rare.

Secret; clandestine.

Hidden, secret, underhand, clandestine.

Private, secret, confidential. In later use also: unspoken, tacit.

attributive. Done under letter of cachet; privy, secret.

(a) = cloak and sword adj.; (b) of, concerned with, or characteristic of espionage, secrecy, intrigue, etc.; hence in various allusive phrases; hence…

transferred. Furtive, secret, sneaking.

Quiet, secret, confidential.

That is ‘in the closet’ (see phrases 2d(a)); not open about one's homosexuality or any other aspect of one’s sexual or gender identity. Also…

Secret, quiet, low-profile; (in later use) spec. of or relating to men who secretly engage in homosexual activity.